Pastoreková S, Parkkila S, Parkkila A K, Opavský R, Zelník V, Saarnio J, Pastorek J
Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Gastroenterology. 1997 Feb;112(2):398-408. doi: 10.1053/gast.1997.v112.pm9024293.
BACKGROUND & AIMS: CA IX (formerly MN protein) is a carbonic anhydrase isoenzyme whose expression is associated with human tumors. However, it has also been found in normal gastric mucosa. The aim of this study was to determine differences in complementary DNAs (cDNAs), to obtain an overview of distribution in the alimentary tract, and to obtain data on expression in tumors.
A CA9 cDNA isolated from a human stomach library was sequenced along with the cDNA derived from HeLa cells. Western blotting and immunohistochemical analyses of human and animal tissues were performed using CA IX-specific monoclonal antibody and rabbit antiserum to human CA II. RESULTS; Sequence analysis showed no differences between the stomach- and HeLa-derived cDNAs. CA IX was detected at the basolateral surface of gastric, intestinal, and gallbladder epithelia. In stomach tumor samples, expression of CA IX was lost or reduced.
Differential distribution of CA IX in normal and tumor tissues is not associated with cDNA mutations. Evolutionary conservation in vertebrates as well as abundant expression of CA IX protein in normal human gastric mucosa, but not in derived tumors, indicate its physiological importance.
碳酸酐酶IX（曾称MN蛋白）是一种碳酸酐酶同工酶，其表达与人类肿瘤相关。然而，在正常胃黏膜中也发现了它。本研究的目的是确定互补DNA（cDNA）的差异，概述其在消化道中的分布，并获取其在肿瘤中表达的数据。
对从人胃文库中分离出的CA9 cDNA以及源自HeLa细胞的cDNA进行测序。使用CA IX特异性单克隆抗体和抗人CA II兔抗血清对人和动物组织进行蛋白质免疫印迹和免疫组织化学分析。结果：序列分析显示胃源和HeLa源的cDNA之间没有差异。在胃、肠和胆囊上皮细胞的基底外侧表面检测到CA IX。在胃肿瘤样本中，CA IX的表达缺失或减少。
CA IX在正常组织和肿瘤组织中的差异分布与cDNA突变无关。脊椎动物中的进化保守性以及CA IX蛋白在正常人胃黏膜中大量表达而在衍生肿瘤中不表达，表明了其生理重要性。
